Apparatus and method for molding concrete blocks



Aug. 14, 1945. F. A. WILLIAMS ET AL APPARATUS AND METHOD FOR MOLDING CONCRETE BLOCKS Filed June 9, 1944 4 Sheets-Sheet l 1945- FQ A. WILLIAMS EI'AL 2,382,458

APFARATUS AND METHOD FOR MOLDING CONCRETE BLOCKS Filed June 9, 1944 4 Sheets-Sheet 2 I j Y M -n'oevnbrs 9 IF. A. wflharns g- 14, 1945- F. A. WILLIAMS ET AL 2,332,458

APPARATUS AND METHOD FOR MOLDING CONCRETE BLOCKS Filed June 9, 1944 4 Sheets-Sheet 3 Aug. 14, 1945.

F. A. WILLIAMS ETA L 2,382,458

APPARATUS AND METHOD FOR MOLDING CONCRETE BLOCKS- Filed June 9, 1944 4 Sheets-Sheet 4 Patented Aug. 14, 1945 APPARATUS AND METHOD FOR MOLDING CONCRETE BLOCKS Francis A. Williams and Geza G. Rusznyak,

Toronto, Ontario, Canada Application June 9, 1944, Serial No. 539,522

16 Claims.

This invention relates to the manufacture of building blocks, made of concrete or other plastic material, used in the construction of the walls of buildings or other structures.

The use of vibration for the purposes of (1) Compacting concrete or other cementitious material and/or (2) Facilitating its extrusion from the form or mold is not new. However, the above mentioned two functions of vibration, viz: compaction and free extrusion have not been employed in the manufacture in great quantity of commercial building blocks i. e. blocks of predetermined uniform height and having also a top which is level and of equal density with the rest ofthe body of the block. The reason of this is that the detaching or severing of units so that all surfaces of the block would be straight, plain and hard did not seem possible.

There are known methods in which a vibratin form is slowly drawn upwards, compacting and freeing concrete to form a building column at the site of the construction, but the finishing possibilities of this method are limited to the sides of the unit and the top is left loose and uneven.

There are also machines which sever the material in the mold by knives introduced at right That is, first, not mass production but individual handling of a building element, and second, in exceptional cases, where such a column is not covered by another building element, such a girder, plate, etc, and the column itself has to have a horizontal top, hand tamping and trowelling are used to form a smooth, plane upper surface. Such a procedure i. e. compacting and freeing by vibration and then tamping and trowelling of the upper surface by hand would be uneconomical in ,the case of mass-production of blocks. (Naturally machine tamping cannot be and is not used combined with free extrusion of the block under vibration for obvious reasons.) There are, of course, simple block-making machines in use in which the compacting is done by hand-tamping, but they are very slow, and usually require a richer mixture.

There are also machines which make concrete angles to the travelling direction of the concrete, and which let the material below them glide from the mold, the knives temporarily withholding the material above them. These machines do not use vibration for compaction and their use is limited to the making of solid (not hollow) blocks, for reasons explained later. They compact the material by simply letting it drop down when the knives are withdrawn and they rely on the weight of the comparatively loose material to free itself from the mold.

The reason why all these previous machines failed to use vibration for free extrusion in connection with making blocks or other objects of a predetermined height and with hard and level tops is the fact that the blocks could not be led out from the mold under vibration without destroying the horizontal top or upper surfaces of the blocks.

The type of vibration used with these bottom-' less molds for making columns, etc. (rotating vibration or agitating the mold walls horizontally from the inside of the mold) produces a slapping motion of the mold walls against the material in the mold, which slapping motion of the wallsdrives the material of the upper part of the block towards the center, destroying the straight horizontal top surface and making it convex, viz; low at the corners and high in the middle. Due to e e e s y gh frequency of the vibration, the destruction is done'within a fraction of the time needed to free the block from the mold by vibrated extrusion. The same slapping motion also loosens up the upper part of the block, so that it loses its density. This slapping motion also damages the web of the widely used hollow blocks. All this makes it extremely difllcult to extrude a block when other than vertical vibration is employed.

Any vibration which produces circular motions in the compacting concrete, such as for instance that caused by an eccentric rotor directly fastened to the mold, can under certain circumstances cause even additional trouble, as strong counter- .currents can be generated in the material and the result of this is that the block, after descendin in the mold is of difierent density at one end to that at the opposite end, besides resulting in weakened corners or edges and some soft spots.

In the prior application of Francis A. Williams, filed Oct. 1st, 1942, Serial No. 460,462, is disclosed, a method and apparatus for the purpose of overcoming theabove difficulties. The concrete is fed, according to the above invention, more or less continuously into an open top and bottomless mold, in which mold the concrete is vibrated, said vibration having two objects, first to compact the concrete into a dense mass, capable of holding its shape, and second, to facilitate the extrusion of the compacted mass from the mold. the extruded compacted material being severed from the mass above it as soon as suflicient material has been extruded to form a block of the desired height.

Though the method set out in said patent application serves its purpose very well, the present application is intended to give still better results.

The present invention, for the purpose of overcoming the diificulties set out above, has the following objects:

1. To determine the proper type of vibration and the proper method of applying it.

2. To provide new means and method for maintaining the flat upper surface of the block while the latter is being extruded from the mold.

3. To provide an arrangement, of the vibrating system which absorbs the horizontal or slapping vibrations without transmitting them to the frame of the machine and thereby obviate the need of permanent, built-in foundations, thus making the apparatus portable.

4. To eliminate the use of a measuring box, which heretofore has been a necessary feature of such vibrating machines as handle at one time only the exact quantity of material necessary for the compacted block. These measuring boxes were necessary as a material used (for example, sand and gravel) are of different consistency in different parts of the country, but they required the use of special expensive machinery and a separate operation.

5. To provide a new type of mold, which can be easily adjusted not only for difierent sizes of blocks, but also for diflerent types of blocks, thus eliminating the necessity of carrying with the machine a separate mold for each type or size of blocks, as only sets of cores and some plates have to be carried along.

6. To make a simpler and less expensive machine compared with previous machines of the same capacity.

The improved apparatus and method is hereinafter fully described and illustrated in the accompanying drawings in which:

Fig. 1 is a vertical section of one form of apparatus taken on the line l-I in Fig. 2;

Fig. 2 a horizontal section of the same taken on the line 2-2 in Fig. 1;

Fig. 3 a vertical section taken at right angles to Fig. 1;

Fig. 4 a horizontal section on the line 4-4 in Fig. 1;

Fig. 5 a perspective view of the weight and its operating means;

Fig. 6 a sectional detail of part of the vibrating mechanism;

Fig. 7 a section on the line 'I! in Fig. 6 looking in the opposite direction indicated by arrow;

Fig. 8 a section on the line 'l'! in Fig. 6 looking in the direction indicated by the arrows;

Fig. 9 a view of the mold taken on the line 9-9 in Fig. 1;

Fig. 10 a perspective view of the pallet locking means;

Fig. 11 a. vertical section of a modified form of apparatus; I

Fig. 12 a plan view of the same;

Fig. 13 a longitudinal detail of the core support shown in Figs. 11 and 12 Fig. 14 a cross-sectional detail of the same;

Fig. 15 a plan cross-sectional detail of the same;

Fig. 16 a detail of one of the core sections;

Fig. 17 a vertical section of the vibrating means shown in Fig. 11;

Fig. 18 a plan view of another form of block;

Fig. 19 a perspective view of the knife operating means shown in Fig. 11;

Fig. 20 a view illustrating the method of controlling the pallet locking means of Fig. 10; and

Fig. 21 a plan view of one of the spring members shown in Fig. 20.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

The drawings show constructions where the main parts are made of wood, but it will be evident that they may be made of other material.

Referring now to Figs. 1, 2, 3, 4 and 5, the apparatus comprises a supporting frame of a construction in which the various parts'of the frame are arranged to give rigidity of construction as well as convenient means for supporting the various operating parts. The frame comprises four vertical corner posts I, which are held in proper relationsh'ip by suitable horizontal members. Mounted within the frame is the mold, the height of which mold is chosen so that when filled level with its top with loose material, said material, when later compacted, will form a block of approximately the desired height. In other words,

the mold is considerably highe than the finished compacted block.

To avoid the slapping of the walls of the mold a purely up and down vibration is employed. Now this type of vibration, though produced in a different way, has been used already in block-making machines of fundamentally different construction and for quite different reasons. Such earlier machines with reciprocating up and down vibration are not free-extrusion machines and so the prob- 16m of not being able to extrude the block from the mold under vibration, let alone the diillculty of the loosening and the convexing of the upper surface, did not even occur there. This type of vibration was obviously used to avoid the above mentioned danger of the rotating vibration, viz: unequal density. Other block-making machines overcome this danger by using every-direction vibration, which again would be unusable in the present apparatus for the reasons explained above. To accomplish the desired result the mold is arranged in the following manner. Positioned within the frame are a pair of mold-carrier members 2, which are caused to reciprocate in a vertical plane by means of apparatus which will hereinafter be described more fully.

The upper ends 2 of these carrier members form the outer side walls of the mold structure,

and are connected together by outer end-members,

3'. The outer mold structure is held .in spaced relation to the main part of the inner surface of the frame I by guides 4 at one end of said frame and by adjustable screws 5 at the other end threaded'through said frame and engaging bearing angles 6 on the end of the mold structure. Similarly one side of the mold structure bears against guides 4, while adjustable screws 5 are provided at the opposite side. The adjusting screws will bear against the mold walls sufiiciently tight to prevent any tipping or horizontal bumping of the mold structure, but do not obstruct vibration in the vertical direction.

ihe adjusting screws may be provided with enlarged feet to provide a large bearing surface against the mold reinforcements 6.

It will be seen from the foregoing description that sidewise or slapping movement of the mold is limited to a minimum while free vertical movement is permitted.

To obtain this desirable vertical reciprocation of the mold with a minimum of side slapping action, the means of vibrating the mold is arranged as illustrated in Figs. 1, 3, 6, '7 and 8 of the drawings.

i is the drive shaft from which the mold is vibrated. 8 are supporting frames which are arranged to rock on a fulcrum 9. These frames 8 are provided with opposedsprings l and H which tend to hold the frames in centered position. Each frame has a shaft H at its upper end from which depends a swinging link I3, which is provided with a ball bearing l4 near its lower end in which said drive shaft 1 is journalled. The shaft i is driven from the motor [5, the drive shaft of which is arranged'in approximately axial alinement with the shaft H2.

The shaft extends through an eccentric bearing I5 mounted in the lower end of link iii, the upper end of which link is pivotally connected with the lower end of the adjacent mold carrier member 2. It will be noted that the main drive shaft 1 may move sidewise since it is supported in pendulum fashion. Theoretically this main shaft is swinging along an arc drawn around the upper axle and is not moving on a straight horizontal line. In reality the horizontal amplitude, about of an inch, is so small and the joints and supporting elements of the machine so far from being ideally exact that in practice the vibration of the shaft can be considered taking place on a short horizontal straight line; The amplitude of the vibration is controlled by the eccentricity of the eccentric bushing l5 secured to the shaft and rotatable in the bearing I5. The mold is guided between the feet of the screws 5 and the guides and can move vertically only as mentioned above. While the swinging shaft itself easily gives way horizontally, instead of forcing the mold to vibrate horizontally, it cannot turn round without pushing the mold upwards and pulling it down again through the rotation of the eccentric bushing i5 in the bearing l5 in the link 16.

This is forced amplitude, which cannot be diminished by the load in the mold or by pressure exerted against the mold, as is the case with eccentric rotors directly attached to the mold which, in case of too heavy a load may rotate without lifting the mold. The control of the amplitude in existing machines is done in different other ways, for instance, by using an eccentric rotor, which has been chosen so that it would produce too much amplitude. The excess amplitude is then cut down by ,bumpers, i. e. by force, t the necessary dimension. Similarly, the horizontal vibration in existing machines is taken by bumpers within the frame construction proper, that is, by force, instead of horizontally yielding shafts, and led down to the foundations. All this requires built-in foundations, and the machine is thus not portable and is expensive. According to the present system the shaft 1 which freely gives way horizontally and changesthe direction of its swinging without hitting anything, and is further mounted on the rocking frame 8, does not transmit substantial vibration, except the vertical one, to the mold frame. Even this vertical vibration is transmitted so The mold as described is open at the top to receive the material for forming the blocks, and open also at the bottom so that the formed block may be extruded therethrough. To receive the formed block from the mold a pallet I1 is provided. The pallet is carried by a movable platform 43, vertically slidable on the main frame, said platform being provided with rolls i9, which directly carry the pallet. This platform may be raised and lowered by means of any suitable mechanism. In the present case it is raised and lowered by hand operation. Spring devices, such as ordinary spiral balances used for window sash and what are known as pullman balances may be provided, which spring devices will tend to lift the platform to upper position, and thus counterbalance the weight of the platform. It will thus be a simple matter for the operator to raise or lower the platform as the newly formed block is the only weight the operator has to hold against downward movement.

Other counterbalancing means, such as weights, etc. might, however, be substituted for the spiral balances.

The reciprocating up and down vibration, as far as the walls of the mold or the cores are concerned, has mostly a trowelling effect only, which eliminates the above mentioned harmful effects of the slapping walls, but produces a very 40 slow and imperfect compacting of the material.

Therefore the pallet I1 must vibrate with the mold, but only during the time of compaction. The reciprocating up and down motion of the pallet is the ideal way and direction to agitate the mass of, and not the surface only of the plastic material, which is set free by this agitation to be pulled down by gravitation. In order to free the compacted block, the walls of the mold must continue to vibrate, but the pallet must cease vibrating at the very moment it starts to go down with the newly formed block, lest the vibration destroy the unprotected or unconfined part of the block while the latter is being freely extruded from the mold. Such a behaviour of the pallet may be obtained in different ways.

One method of accomplishing this result is by means of the pallet lifting and locking means, shown particularly in Figs. 1, 3, 10 and 18. Such lifting and locking means are arranged below the pallet and simply rest on the movable platform 43, without being fastened to the latter. The locking means comprise a pair of grippers I8-l 9, arranged in telescoping relationship to one another (see Fig. 10). A spring 20 is arranged between these grippers, tending to spread them apart and to engage the opposite ends in recesses 2| in the mold carriers 2. The outer ends of the grippers l8 and I9 are bevelled on their under sides and in expansion the members are raised by said bevelled portions to hold the allet tightly against the under side of the mold. The vibrations also assists in the expansion of the locking means in the event there is any tendency of the latter to stick. These grippers are slidable within a sleeve 15 which holds them in proper sliding relationship.

The grippers I8 and I! are moved to and held in retracted position by cables 22 which are r guided over suitable pulleys 23-24 and conncted to cams 25 on the shaft 26 on the main frame I. The earns 25 are connected by a rod 21, which rod acts as a handle by means of which the cams are rotated to release orretract the grippers l8 and 18. This rod 21 at the same time serves as a handle to lift and lower the platform 43.

It is desirable, however, to provide other means for holding the grippers l8 and I9 in retracted position, so that it will not be necessary for the operator to maintain them in said retracted position.

Secured by its head-ends to the under surface of each gripper is a spring member 80, which spring members are oppositely directed and lie fiat against the under surfaces of the grippers. Extending downwardly from each gripper is the shoulder 6|, which projects into the spring member of the other gripper, and thus the interengagement of the shoulders and spring members normally tends to hold the gripping members in retracted position. To disengage the spring members 60 from the shoulders 6|, when the platform 43 is raised, in order to permit the grippers to engage in the notches 2|, a cable 62 is provided, the lower end being secured to a fixed part of the frame and its other end connected with the spring members 60. As the platform 43 is moved upwardly, the cable 52 becomes taut and as the platform moves to its upper position with the pallet in engagement with the mold, the cable bends the spring members 60 downwardly to disengage them from the shoulders 6|, thus allowing the spring 20 to move the grippers l8 and I9 into the notches 2 I. After the grippers have been retracted by the operator by means of the handle 21 and associated parts, the platform is allowed by the operator to move downwardly with the new block and the cable 62 gradually slackens, allowing \the spring members 60 to flatten and engage the shoulders 6|.

vWhen the pallet is locked against the bottom of the mold, it becomes part of the mold system and is vibrated therewith. This vibration will cause the platform 43, which is balanced by the spring devices referred to above, to temporarily move slightly, so that the rolls I9 are out of contact with the pallet, said platform being again raised, when compacting is completed, ready to receive the pallet when the locking means is retracted and the pallet released from the mold carriers 2.

The rolls [9 while carried by the movable platform 43, are mounted on supporting posts 44 vertically movable in sockets in said platform. Springs 45 tend to hold the posts raised in said sockets. When the platform is raised, the pallet I1 is thus resiliently held against the under side of the mold.

While the use of the pallet-locking means above described is preferable, in some cases this pallet locking means could be omitted and the springs 45 entirely depended on to hold the pallet against the mold during vibration. This spring method, however, while fairly satisfactory, has one drawback, viz. that by pressing the pallet against the mold, even through springs, but from a point outside the mold, one is acting against vibration, and this resistance to vibration increases the more the springs are Cooperating with the movable platform 4: is

a fixed platform 28 having rolls thereon to receive the pallet with the extruded block thereon from the rolls IS on the platform 43. A fresh pallet is then positioned on said rolls l9 and the old pallet with the block on it is pushed on to the fixed platform 28 by the operator, by means of the new pallet, when the latter is being placed on the roll of platform 43.

Building blocks are generally made in various widths to meet the requirements of the structure being built. Referring particularly to Figs. 2 and 9, it will-be noted that the mold carrier 2, the upper ends of which form the mold side walls, are each formed of two parts 2 and 2 secured in spaced relationship by the end members 3 to give strength to the mold structure.

Within the mold side walls are the side liners 2 and end liners or spacers 3*, which comprise the mold proper, which liners are preferably formed of, or faced with metal, to withstand wear from the material passing through the mold. Between the inner side members 2 and the side liners 2 may be positioned filler members 2 and 2*.

When it is desired to form a block, say eight inches wide, both side fillers 2 and 2' will remain in place. If it is desired to form a block ten inches wide, the inner fillers 2 will be removed and end liners or spacers 3 ten inches long, substituted. If it is desired to form a block twelve inches wide, the fillers 2 will also be removed and end liners 3 twelve inches long substituted. It will be readily seen that it is a comparatively simple matter to re-arrange the mold for making blocks of different widths. If it is desired to provide the mold wall with vertical ribs or grooves, the liner members 2 and 3 may be suitably patterned to give the desired effect. In Fig. 2 one side and one end is shown arranged to form a rib design.- The filler members are frictionaily held in proper position in the mold by means of set screws 29, threaded through one of the mold sides 2, as shown more clearly in Fig. 9.

In most cases the blocks will be provided with recesses or openings, and the cores which form these recesses are arranged as follows. The cores 30 are suspended from a transverse support 3|, extending longitudinally of themold and secured to transverse end members 32, which rest on lugs or cleats 33 secured to the mold end 3, intermediate the vertical guides 4 and adjustable,

screws 5.

The cores 30, the support 3| and the end members 32 are joined together to form a unit, movable as a whole, and said core unit is secured in place by bolting the end members 32 to the lugs or cleats 33. It is a simple matter, therefore, to remove a core unit, as it is simply necessary to disengage the end members 32 from the cleats 33, lift the core unit out, and substitute another unit, when larger or smaller cores are desired for making any particular width of block.

As pointed out, it is desired to avoid the use of separate measuring boxes, and to utilize the mold itself as the measuring box. As it has also been previously mentioned, the mold is of a size to hold enough loose or uncompacted material to form a compacted block of the desired height, which naturally is less than the height of the mold. Mounted above the mold is a tray 64 having a flange 65. The bottom of this tray is sary extra capacity, one or more fillers 66 may be provided between the top of the mold and the ations, when it is desired to hold the weight out of action.

The idea of combining vibration with the pressure of a weight to compact plastic material is 5 not new, but in the present case the weight has under side of the tray. These fillers are simple plates of a suitable thickness, and formed, like the tray 64, with an opening or openings, cons forming to the horizontal cross section of the block. Once the proper height has been provided for the aggregate from a given locality, it is simply necessary each time to fill the mold to the upper surface of the tray, and screed off any extra material, to have just sumcient material to form a block of the desired height.

If the machine is moved to another location where the aggregate has slightly more or less fines, one or more fillers 66 may be removed or added as may be necessary.

As previously pointed out, it is necessary to prevent any loosening or convexing of the upper part of the block through vibration after com.- pacting has been completed, and, for this purpose, is provided a weight 34, suspended by cable 35 from the top of the frame I. Below this weight is supported by legs 36 a pressure plate 37, having openings therein corresponding with the arrangement of the cores. This pressure plate is positioned on the material in the mold and remains there during the compacting vibration and. also follows the block during the extruding vibration. The effective pressure of the weight 38 is varied to suit the requirements. It will be noted that a counterweight 38, slightly lighter than the weight 33, is connected with the outer end of the cable 35 through the intermediate cables 35. This counterweight is vertically movable on a guide rod 39. Due to the counterweight 38, the weight 34 may be easily manipulated to move it to and from its working position on the material in the mold. When it is desired to utilize the entire weight of said weight 35, to assist in compacting the material in the mold, means are provided for lifting the counterweight 33 out of action. In Fig. 5 the counterweight 38 is shown in dotted lines in a partly raised position (at which time the weight 34 rests on the material in the mold), and a lifting lever 33, pivoted on a part of the frame I, is provided for further lifting the counterweight to permit the weight 34 to rest heavily on the top of the material in the mold. I I

The pivot I6 for the lever 39 is arranged to permit suflicient sidewise movementof the lever to allow the counterweight to pass, as shown in Fig. 2, said lever being then moved first laterally under the counterweight 38 and then rocked vertically to lift the latter. A stop 69 on the support I limits the rocking of the lever 39, and thus limits the lifting of the counterweight 38 by said lever. A spring 40 normally tends to hold the lever 39 out of the path of the counterweight in a downward position. The weight 34 is held in proper position by arms 4| engaging the corner posts of the main frame I. A hook 68 depending from an eye 61 on the under side of the top of the support is provided for engaging an eye 69 on the weight 34, to hold the latter raised during the filling of the mold, or during other opertwo diflerent functions to fulfill, and therefore means are provided, as mentioned above for altering the effective pressure of said-weight. Due to the counterweight it moves down easily until it sits on top of the loose material. While the weight is helping the vibration to compact the material, it is heavy, due to the lifting of the counterweight. At this time the rope 35 is loose and the heavy weight is bouncing on the top of the material as soon as the latter becomes halfway compacted and offers some resistance. The bouncing does not correspond with the frequency of the vibration, and the result is a pounding or tamping of the material by the heavy weight, which is the equivalent of a much stronger pressure than could be exerted with such simple devices. As soon as the material has been compressed to the prescribed height, the rope tightens automatically due to the stop 69, being engaged by the lever 39 and thus preventing the further lifting of the counterweight by said lever. The counterweight 34 thus loses its compacting action due to the counterweight again becoming effective. The weight 34, although counterbalanced by the counterweight 38 is, however, sufficiently effective to counteract the forming of a convex top' and the loosening of the upper strata as it follows the block downwardly during extrusion, but is not so heavy that it would destroy the block, while the latter is being extruded. At the bottom of the mold the weight 34 stops automatically by the counterweight engaging the stop 10 and can be pulled up easily again due to the counterweight. This method works even in case of a certain amount of slapping of the walls, that is, if the up and down vibration is less pure than that produced by our system, but a very strong rotating vibration produces a convex top even below the descending weight.

' The double function of the weight 34 may be obtained by means of a single lever, to whichdifierent pressures may be applied, to suit the requirements.

In Figs. 11 and 12 are illustrated not an alternative complete apparatus, but alternative individual features, any or all of which may be substituted for the corresponding feature of the apparatus shown in Figs. 1 to 4.

For example, the weight 34 and its associated parts may be dispensed with.

As an alternative, an excess of material over that, required for the compacted block, is dumped on the mold, which in this case has the same height as the blocks to be formed and the end walls 3, only are made somewhat higher, to prevent excess concrete from spilling oif the top of the mold. The mold in this case is vibrated during the filling to compact the material therein. As soon as the material is compacted, the'excess material is severed by knives 46-41, which are provided with, suitable hand grips, are detachable and may be manipulated as hand trowels.

To give enough power to operate the knives, to

make a clean separation of the excess material the following means is provided. Journalled at opposite sides of the frame are shafts 5| and 52. Adjacent each end of the shaft 5| are pairs of gears 53-55, while adjacent each end of the shaft 52 are pairsof gears 54-55. The gears 53 are rotatable with the shaft while the gears 56 are rotatable relative to the said shaft. Similarly the gears 55 are rotatable with the shaft 52, while the gears 54 are rotatable relative to the shaft 52. Secured to the gear 53 at one side of the machine is one end of a. chain belt, which extends over the corresponding loose gear 54 on the shaft 52. Also secured to the gear 55 on the shaft 5| at the same side of the machine is one end of a chain belt 50, which extends over the loose gear 55 on the shaft 5|. The other ends of these chain belts extend downwardly and are connected to a foot lever H.

At the other side of the machine endless chain belt 49 and 50 are mounted on the cooperating gears 5354 and 55-55.

The knife 46 is provided with one or more fingers at each end, which are adapted to enfoot lever II, to move the chains so as to draw the knives towards one another over the top of the mold surface, to thus separate the excess material from the compacted block and also to form the straight, level top of the latter.

As the compacted block moves downwardly after being out, there will be no convexing of the top, due to the fact that the vibration is limited to a reciprocating up and down motion, which, as pointed out, mainly exercises a trowelling effect on the sides of the block.

In Figs. 13, 14, 15 and 16 is shown a corresponding arrangement of the core, from the type of machine shown in Fig. 11. In this arrangement the cores are carried by a longitudinal supporting bar 51, which rests on the end members 3 of the mold. Depending from this bar 51 are core frames 58, which form central parts of the core sides. Detachably connected with the ends of these frames 58 are core end sections 59, one of which is shown clearly in Fig. 16. Each section is provided with an upwardly directed tongue 59 which, projects into the supporting bar 51, while its lower end is bolted to the frame 58. The holes 80 for the securing screws are arranged a little lower than the corresponding holes 6| in the frame, and consequently in forcing the screws home, the core section 59 will be lifted tightly against the supporting bar 51. When a wider or narrower block is to be made, the cores may be readily altered by providing sections 59 of larger or smaller transverse cross section.

As previously pointed'out one of the important features of the invention is the elimination of the horizontal vibration or slapping of the mold Walls, and in Figs. 1, 3, 6, 7 and 8 is shown one form of vibrating mechanism.

A more simple form is shown at the bottom of Fig. 11 and in more detail in Fig. 17. In the construction shown in Fig. 8, the shaft I2 is supported in a tiltable support 8. In Fig. 1'7, the corresponding shaft I2' is directly mounted on the frame I, the shaft 1 being supported pendulum fashion from the shaft I 2.

To sum up, it is desired to again emphasize that we have devised apparatus in which the vibration of the mold is substantially in the up and down direction only, that is, in the same direction as the material travels through the mold, so that the mold side walls, when moving up and down, exercise only a trowelling action on the sides of the. block and the actual compacting of the material in the mold is effected by means of the pallet being held against the lower end of the mold and being vibrated by the latter. It vibrates up and down with the mold only during the periods of time it is desired to vibrate the material above the pallet. At other times the pallet is separated from the mold, and during these times the pallet is not vibrated, and hence exerts no vibrating action on the mass of the block above it, but provides a steady support for the yet unhardened block during its extrusion. The 'convexing and loosening up of the top of the block, while the latter is being extruded, is eliminated by the special up and down vibration, and in the case of the machine shown in Figs. 1 to 5 also by the described double function of the weight 34 (or a lever). The combination of (1) compaction by vibration and (2) free extrusion, without damage of the severed and finished unit, is possible only by the use of the vibratable and detachable pallet together with the reciprocating vertical vibration.

Finally it is desired to mention that the process and apparatus above described is particularly adapted for the manufacture of blocks, such as shown in Fig. 18, which shows an insulating block of the lamellated type. In this form of block the much larger area of core-surface and the friction caused thereby, makes it difficult to free the block with the older methods. Our method of vibrated free extrusion eliminates the friction between the material and the core or mold surfaces. The free extrusion is assisted by the described action of the weight 34.

What we claim as our invention is:

.1. In apparatus for forming building blocks,.

a supporting frame; carrying means vertically movable in said frame; a mold carried by said carrying means; a drive shaft swingably supported relative to said frame; eccentric means in said shaft; and means for eflecting the vertical movement of the carrying means from said eccentric means.

2. In apparatus for forming building blocks, a supporting frame; carrying-means vertically movable in said frame; a mold carried by said carrying means; means for vertically vibrating the carrying means, and mold; a platform below the mold and movable vertically relative thereof; a pallet carrier on said platform; and means for temporarily holding said carrier with the pallet against the under side of the mold to subject the pallet to vertical vibration with the mold.

3. In apparatus for forming building blocks, a supporting frame; carrying-means vertically movable in said frame; a mold carried bysaid carrying means; means for vertically vibrating the carrying means relative to the frame; a platform below the mold and movable vertically relative thereto; a pallet carrier normally resting on said platform; and releasable interengageable means on said carrying means and carrier for temporarily locking said carrier with the pallet in engagement with the under side of the mold to subject the pallet to vertical vibration with the mold.

' 4. In apparatus for forming building blocks, a supporting frame, said mold having an open top; a mold vibratable in said frame; a cable having at one end a main weight alined with asea4ss and movable vertically relative to the open top of the mold and at its other end a counterweight of less weight than the main weight; and means for independently supporting the counterweight.

5. In the molding of blocks of concrete 'or other self-hardening material employing a vertical tubular mold and a separable pallet, the process of supporting the pallet against the bottom of the mold; feeding material into the mold, subjecting the mold and pallet to a vertical vibration to compact the material, and subsequently moving the pallet slowly downwardly without vibration from the mold while continuing said vertical vibration of the mold to extrude the compacted material.

6. In the molding of blocks of concrete or other self-hardening material employing a vertical tubular mold and a separable pallet, the process of supporting the pallet against the bottom of the mold; feeding material into the mold, subjecting the mold and pallet to vibration while applying pressure on said material from above to compact the material, and relieving the compacted material from a portion of said pressure while moving the pallet slowly downwardly from the mold and while continuing said vibration to extrude the compacted material.

7. In the molding of blocks of concrete or other self-hardening material employing a vertical tubular mold and a separable pallet, the process of supporting the pallet against the bottom of the mold in positively locked relationship; feeding material into the mold, subjecting the mold and pallet to a vertical vibration to compact thematerial, and subsequently moving the pallet slowly downwardly without vibration from the mold while continuing said vertical vibration of the mold to extrude the compacted material.

8. In the molding of blocks of concrete or other self-hardening material employing a vertical tubular mold and a separable pallet, the process of supporting the pallet resiliently against the bottom of the mold; feeding material into the mold, subjecting the mold and pallet to a vertical vibration to compact the material, and subsequently moving the pallet slowly downwardly without vibration from the mold while continuing said vertical vibration of the mold to extrude the compacted material.

9. In the molding of bloocks of concrete or other self-hardening material employing a tubular mold and a separable pallet, the process of supporting the pallet against the bottom of the mold; feeding material into the mold, subjecting the mold and pallet to vibration to compact the material, and subsequently moving the pallet slowly downwardly without vibration from the mold while continuing said vibration of the mold to extrude the compacted material.

10. In apparatus for forming building blocks. a supporting frame; carrying-means vertically movable in said frame; a mold carried 'by said carrying means; means for vertically vibrating the carrying means and mold; a platform below the mold and movable vertically relative thereto; and means interposed between the platform and pallet for resiliently holding said pallet against the under side of the mold.

11. In the molding of blocks of concrete or other self-hardening material employing a vertical tubular mold and a separable pallet, the process of supporting the pallet against the bottom of the mold; feeding material into the mold and at the same time subjecting the mold and pallet to a vertical vibration until the mold is filled with compacted material; removing any excess material from above the mold, and subsequently moving the pallet downwardly without vibration from the mold while continuing said vertical vibration of the mold to extrude th compacted material.

12. In apparatus for forming building blocks, a supporting frame; a mold; means for vertically vibrating the mold relative to the frame; a platform below the mold and movable vertically relatlve thereto; a pallet-carrier loose on the platform; and releasable interengageable means between said mold, vibrating means and said pallet carrier for temporarily supporting said carrier with the pallet in engagement with the under side of the moldto subject it to vibration with the latter.

,13. In apparatus for forming building blocks, a

supporting frame; a mold adjustable in height and vibratableinsaid frame, said mold having an open top; a cable having at one end a main weight allned with and movable vertically relative to the open top of the mold and at its other end a counterweight of less weight than the malnweight; and means for independently supporting the counterweight.

14. In the molding of blocks of concrete or other self-hardening material employing a vertical tubular mold and a separable pallet, the process of supporting the pallet against the bottom of the mold; filling the mold to its upper level with the self-hardening material; subjecting the mold and pellet to vertical vibration .to compact the material and then subsequently moving the pallet slowly downwardly from the mold without vibration, while continuing said vertical vibration of the mold to extract the compact material.

15. In apparatus for forming building blocks, a supporting frame; a mold vertically vibratable in said frame; a pair of upwardly extending shaft supports rockable on the lower part of said frame;

swinging links depending from the upper part of each of said supports, a drive shaft journalled in the lower ends of said links, eccentric means on said shaft; means for actuating the mold from said eccentric means; and resilient means for supporting said shaft supports in centered vertical position.

16. In apparatus for forming building blocks, a supporting frame; a mold vertically vibratable in said frame; apair of swinging links having their upper ends pivoted on the frame; a drive shaft journalled in the lower ends of said links, eccentric means on said shaft; and means for actuating the mold from said eccentric means.

FRANCIS A. Wm Ms. GEZA G. RUSZNYAK. 

